The smooth dogfish has a
slender body with an obvious spiracle behind the eye. The caudal fin has a
rounded lower lobe and a larger top lobe. The teeth are very small, blunt,
numerous and similar in both the upper and lower jaw. This shark is olive gray
or brown on top and yellow or grayish white below. The smooth dogfish is able
to change its colour slowly through contraction of melanophores (migratory
pigment cells that through contraction or relaxation give the impression of a
colour change). This shark grows to 1.5 meters (5 feet) in length. It is
primarily nocturnal.

Diet

This shark is a scavenger
and opportunistic feeder, but regularly feeds upon crabs, lobster and
shrimp.

Reproduction

The smooth dogfish is a
viviparous shark giving birth to a litter of 10 to 20 pups. Gestation is 10
months long and the young are usually delivered in the summer months. The pups
are 34 to 39 cm (13 to 15 inches) at birth. Sexual maturity is reached when
individuals reach 85 cm (33 inches) in length.

Habitat

This shark commonly lives
in bays and inshore waters. It prefers waters less than 18 meters (60 feet)
deep. The smooth dogfish is a migratory species that moves north and south with
the seasons.

Range

This species of shark
occurs in the western Atlantic Ocean. It ranges from the Bay of Fundy to
Uruguay. It is a common shark in the waters off Cape Cod to Delaware Bay, and
overwinters from Chesapeake Bay to South Carolina. It is rare in Canadian
waters and the Bay of Fundy represents the northern most part of its
range.